Once the site is designed and filled, you need to host it. That means putting it on a computer that other people can see. Running that computer takes an entirely different set of skills.
The most popular option is a free site hosted by WordPress.com. They keep the software up to date, protect it from viruses and other nasties, and make regular backups. The downside is you have fewer options for customization.
A paid site hosted by WordPress.com gives you more options and lets you choose your own web address. You can upgrade from free to paid at any time. This is approximately $100 per year.
Your website can be hosted elsewhere. This gives you even more options, but requires slightly more work by me. This costs about $100 per year ($80 for the host, and $20 for domain name (web address) registration, usually sold as a single package . You (or I) have to keep the software current and secure, and make regular backups. (Hosts make backups for their own use, and usually do not back up user content. This takes me extra hour or two a year unless there is a problem. ) Check with me before choosing a host. Some of them are reputable. Some of them are sneaky if you don’t know what questions to ask.